Sustainability projects are a central component of engineering today – from solar panels and wind turbines that supply alternative energy to electric engines and cleaner oil refining, engineers are helping us do right by our environment. But one non-renewable resource that we’re still struggling to protect and use more carefully is our water supply. Pollution, the draining of water supplies into agriculture – particularly animal agriculture – and in manufacturing are all a drain on our water supply.

Water reclamation systems, however, are the answer to stretching our water resources further without compromising our drinking water, but few people understand how these systems work so they remain in limited use. Here’s a peek at the inner workings of grey water reclamation and how it can be put to use in your community.

Where The Water Goes?

What happens when water goes down the drain? We don’t think about this question often, but rather tend to worry more when a plumbing problem means water isn’t going down the drain – though we know that the answer tends to be into the sewer or septic system and then off to a treatment facility to be cleaned and reused. Next time you’re sitting in a bathtub with the drain stopper in, though, take a look at that dingy water. Sure you couldn’t drink it, but couldn’t you do more with that, like flush the toilet or water the plants?

This is the premise behind water reclamation, that used but not especially dirty water, technically known as grey water, can be used without having to travel back to the plant and chemically cleaned. In order for this to happen, however, you need a special system.

The Basics Of Reclamation

Grey water is the middle state between clean or white water and sewage or black water, and what makes grey water reclamation so valuable is that it still contains important nutrients that can be used to feed plants. Systems that reuse it also can reduce the stress on sewage systems, many of which are already overburdened in heavily populated areas.

The one major challenge is that reclamation poses more contamination concerns than sending water straight for treatment, shouldn’t be used around children or pets, and often requires involved plumbing changes.

A Model Reclamation System

One ideal model for future reclamation projects is the WaterHub at Emory University in Atlanta, Georgia. Emory’s WaterHub uses a hydroponic filtration system to remove major contaminants from grey water, feeding plants in a central greenhouse in the process, and reuses the water for heating and cooling, landscaping, and for toilet flushing on the campus. When running at maximum capacity, it can recycle 400,000 gallons of water per day and the system is the first of its kind in the United States.

Future water reclamation systems may follow this model or other sustainable systems for reuse, but whatever the chosen method, grey water reclamation is the future of water treatment and management in a world that is running short on resources. Clean water is one of our most fundamental needs, and responsible engineers are working hard to improve global access even as demands increase.